This proposal is the second supplemental submitted to expand the SCORE Program now active at the University of Puerto Rico, Rio Piedras campus (UPR-RP). The projects included are one from Chemistry (revised according to the critiques reported in the Summary Statement for our first supplemental application) and three from Biology; two also revised following recent critiques and one presented by a young molecular biologist recruited this past summer by the Department. Together, these new projects aim to conduct competitive biomedical research in areas related to: the regulation of gene expression by environmental signals, in particular nonsense-mediated messenger RNA degradation (Gonzalez); the relation between muscle anatomy, neuromuscular physiology and behavioral development in a honey bee model (Giray); the physical and structural parameters determining protein and peptides secondary structure (Schweitzer-Stenner); and the unique and tissue specific transcriptional and translational processes occurring in cells of a spider silk gland. All of these projects complement well the biomedical research efforts that have been ongoing for over 25 years at the UPR-RP under the auspices of MBRS and specifically strengthen our SCORE Program. The current Program has eleven projects (seven in Chemistry and four in Biology) that just started their second year of support. This number is expected to increase early in 2002 by at least five or six projects through funding of our first Supplemental Application, which is still pending. These investigations are to be sustained by an on-going administrative project and by supplementary technical and support personnel. The proposed growth and diversification of our SCORE Program will provide this institution additional research and development opportunities as well as an expanded and fully supportive research atmosphere. In this way it will enhance the biomedical research productivity, scientific competitiveness and peer recognition of the participating faculty. Research activities in the program also enhance the existing MARC U * STAR Program and the beginning MBRS-RISE Program at this institution. Progress in the specific aims of each new project and in the overall aims of the program will be evaluated yearly through an established Evaluation Plan.